I remember back in the 90s when the station I was working for here in New Zealand started playing the Rick Dees Weekly Top40, and they also played Shadoe Stevens American Top 40.
(I do remember this same station played the Casey Kasem AT40 many years prior to me starting there.)
All of these shows would arrive on vinyl, get played on a Sunday morning between 8 and 12 (usually), and Monday morning when I arrived at work there'd be a stack of vinyl in the bin.
Sadly, I never realised the value or the importance of those albums otherwise I would have grabbed as many as I could. They were issued with instructions to be destroyed as soon as they had been aired, and countless albums were dumped.
I must have picked up a couple of them somewhere along the line as I still have those to this day, but a couple of albums doesn't really count when a whole set is needed to be able to 'play it again, Sam'.
I too would love to hear Casey Kasem's American Top 40 on the airwaves here, so I contacted a company in Australia that holds the broadcasting rights to it. They were more than happy to oblige, and send us the weekly shows - but the cost was unsustainable.
Our community station relies mostly on grants, and we do not have the budget to purchase syndicated shows like this.
I must acknowledge that they were prepared to give it to us at a substantially reduced rate, which was quite reasonable all things considered, but we simply couldn't justify the expenditure.
I then set about looking for someone who has the complete series of AT40, so I could at least transfer them to digital (CD or HD) clean them up and have an 'archive' of the shows. Even if we couldn't air them (copyright and licensing etc) it would still be great just to listen to them privately.
So far I haven't been able to find anyone who has the full series (or even close to it).
Anyway, I left radio around 1994 and didn't come back to it until 2003. By that time all the vinyl had gone, replaced by CDs and internet downloads.